#include <stdio.h>

int main()
{
	int max = 0;
	scanf_s("%d",&max);
	int i = 1;
	while (i < 4)
	{
		int n = 0;
		scanf_s("%d",&n);
		if (n > max)
		{
			max = n;

		}
		i++;
	}
	printf("%d",max);
	return 0;
}